Locomotive spark-arrester



2 Sheets-Sheet 1'.

A. MITCHELL.

LOGOMOTIVE SPARK ARRESTBR.

(No Model.)

Patented Dec. 27,1881.

(No Model.) 2 Sheets-Sheet 2.

A. MITCHELL.

LOUOMOTIVE SPARK ARRBSTER.

No. 251,621. v Patented 1360.27.1881.

N. PETERS. Phnlc-Lflhogmpher. wmhingtm D. c.

I UNITED STATES PATENT OFFICE.

ALEXANDER MlTCHELL, OF VVILKES-BARRE, PENNSYLVANIA.

LOCOMOTIVE SPARK-ARR ESTER.

SPECIFICATION forming part of Letters Patent No. 251,621, dated December 27, 1881.

Application filed September 19, 1881.

To all whom it may concern:

Be it known that I, ALEXANDER MITCHELL, a citizen of the United States, residing in \Vilkes-Barr, Luzerne county, Pennsylvania, have invented certain Improvements in Locomotive Spark-Arresters, of which the following is a specification.

My invention relates to an improvement in that class of spark-arresters which have screens for preventing the admission of large sparks or particles of ignited fuel to the stack, the object of my invention beingto provide effective means for disposing of these large sparks and preventing their accumulation in the smokebox of the engine.

In the accompanying drawings, Figure 1, Sheet 1, is a transverse section of the smokebox of a locomotive, illustrating my invention; Fig. 2, a sectional plan on the line 1 2, Fig. 1, and Figs. 3 and 4views on a smaller scalethan Fig. 1, illustrating modifications of the invention.

In Figs. 1 and 2, A represents the smokebox section of the boiler; B, the front tubesheet; D, the smoke-stack, and E the usual duplex exhaust-nozzle. A screen, F,is secured at its lower end to the nozzle E, the upper end of the screen being secured to the shell of the boiler, so that sparks and ignited particles of fuel must pass through the screen before they can gain access to the stack D, all particles which are too large to pass through the meshes of the screen falling into the bottom of the smoke-box. From this portion of the smoke box to the screen F, at a point some distance abovethe lower end of the latter, extends a liftpipe, G, having at the upper end lateral branches H H, which communicate with external boxes or receptacles, J ,on opposite sides of the smoke-box. The upper end of each of these receptacles J communicates, through a pipe or pipes, a, with the interior of the stack D, the end of each pipe 0. being turned upward within the stack, so that the draft through the latter will induce a draft through the pipes a, from the receptacles J. Within each of the receptacles J is a screen, I), interposed between the mouth of the pipe at and that of the branch H of the lift-pipe, and said receptacles are provided with nozzles d, through which jets of water or steam can be projected into the same,

(No model.)

these jets, being under the control of the engineer, and suitable drip-valves, 6, being provided for preventing the rising of the water or condensed steam in the receptacles to such a height as would permit it to flow through the branches H of the lift-pipcinto the smoke-box of the boiler.

The operation of the deviccis as follows: The large sparks and particles of ignited fuel which drop into the bottom of the smoke-box are caused to rise in the lift-tube Gr, owing to the upward draft caused by the blasts of steam from the nozzle E and by the induced draft through the-pipes a of the receptacles J. Some of the particles may be broken by contact with the lower portion of the screen D, and pass through the meshes of said screen, and thence directly to the stack; but the large particles pass upward through the branches H of the lift-pipe and enter the receptacles J, in which they are deposited, the screens 1) preventing them from entering the stack through the pipes a. 'The sparks are extinguished by the jets of water or steam from the nozzles 01, and are discharged from the receptacles at intervals, the bottoms of the receptacles being pivoted as shown in Fig. 1, or being provided with suitable valved discharge-pipes, in order to facilitate the emptying of the same. By this means the smoke-box is kept clean at all times, the ready escape of the large particles from the latter being provided for, so that said particles are not likely to adhere to and clog the meshes of the screen F, as usual, the draft of the engine being thus unobstructed, and the steaming qualities of the engine not being interfered with.

Various forms of exhaust-nozzles and screens may be used in connection with the lift-pipe and receptacles in carrying out my invention. For instance, instead of the low nozzle and inverted conical screen shown in Fig. 1, I have illustrated in Fig. 3 a high nozzle and a cylindrical or box screen in the upper portion of the smoke-box, and in Fig. 4 I have shown a horizontal screen similarly located.

In Fig. 4., also, I have shown two lift-pipes instead of the sin gle lift-pipe with two branches, one pipe being arranged in front and the other in the rear of the exhaust-nozzle.

I am aware that sparks have been blown from the bot-tom of the smoke-box onto the groundt ing screen in the smoke box, a spark-receptacle from the bottom of the smoke-box into the receptacle.

I claim as my inventio-n- 1. The combination of the smoke-box and its stack, the exhaust-nozzle,thespark-arrestlocated above the bottom of the 'smoke-box, and a lift-pipe communicating with the upper end of the receptacle and with the bottom of the smoke-box, asset forth. 1

2. The combination of the smoke-box and its stack, the exhaustmozzleflhe spark-arresting screen in the smoke-box, a spark-receptaclelocated'above thebottom ofthe smoke-box,

and a lift-pipe surrounding the exhatist-nozzle, and having a branch communicating with the upper portion of said spark-receptacle, as specified. r .t ;I

3. The combination of the smoke-box and its stack, the exhaust nozizle, a spark-receptacle,

a lift-pipe having a branch communicating with said spark-receptacle, a screen extending from the lift-pipe to the shell of the smokebox, and a screen, extending to the exhaustno'zzle from the inside of-the lift-pipe, above the branch of the same as set forth.

.4., The combination of the smoke-box and its stack, a spark-arresting screen, a spark-receptacle above the bottom of the smoke-box, a

lift-pipe communicating with the bottom of 40 the smoke-box and the upper portion of the spark-receptacle, a draft-pipe, a, and a screen, 12, interposed between the pipe to and the liftpipe, and occupying such relation tothe latter that the sparks impinge upon the screen as they emerge from the lift-pip e,;as set forth.

' '5.- The combination of the smoke-box, its

spark-arresting screen andstack, the lift-pipe,

and aspark-receptacle havinga draft-pipe, a, a screen, I), a nozzle, (1, and an overflow, c, as setforth. l c I In testimony whereofl have signed my name to this specification in the presence of two subscribing witnesses. r

. ALEXANDER MITCHELL. Witnesses:

. E..W.ZMULLIGAN, E. L. MULLIGAN. 

